Studies on the Metabolic Products of Oospora astringenes. VII. Biogenesis of Oospolactone and Oosponol

Abstract

Biogenesis of oospolactone (I) and oosponol (n) from a fungus, Oospora astirngenes were studied by using glucose-[1-C14], glucose-[6-C14], malonate-[2-c14], formate-[C14], and uniformly labelled glucose-[C14]. Degradation methods of the 2 metabolites were established and the progress of cultivation was also studied. Skeletons of the 2 metabolites are synthesized from 5 Ca-units according to the "acetate-malonate condensation" and 1 C1-unit, C1-unit is incorporated as methyl-C (carbon 11) in I, and as =CH- (carbon 9) which forms the lactone ring in H. These 2 isocoumarins from the same culture have the different origin of lactone ring.